Polygon grinding machine



Aug. 21, 1956 R. H. RHODES POLYGON GRINDING MACHINE 2 Sheets-Sheet 1 Filed July 15, 1954 m NN .WN mm I cw E NM 9\ t Robert H. Rhodes INVENTOR.

21, 1956 R. H. RHODES POLYGON GRINDING MACHINE Extended plane of generated flat \umm 22:35 z b QSE Emu Q e B EB Etk Robert h. Rhodes IN V EN TOR.

9 By Wm United States, Patent PonYooN oRiNmNo MACHlNE Robert. H..llhodeonfChicagq llh, assignor toBearings "Ma'nufacturint; QCQ PaI Uav Chicago, 111., .a corporation offlllinois' 7 Application July-13, 1954, Serial No. 443,130-

1 'Claim. (Cl. 51-237) This-invention relates generally ,to.grinding-1 machines, and-,has fortits primary object the provision nOf an; improved grinding machine component. wherein polygonal forms are. readily generated.

Another. object of this invention,is.to, provide an,=impmved. work-holding device for grindingmachinos-twhieh Willi carry .a .work piece in an orbitahpath forcqoperation with a grinding wheel whereby flat surfaces may be ground onto a workpiece and 'a-resultant polygonal articlesforrned.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a sectional view taken through the improved work holder;

Figure 2 is a front elevational view of the assembly shown in Figure 1; and

Figure 3 is a diagrammatic view showing the method by which the flat surfaces are generated on the work piece.

Referring now more particularly to Figure l, reference numeral indicates generally a housing or casing which forms the main body of the work support and within which are provided the wall members 12 and 14 between which a drive shaft 16 is journaled by means of the bearing members 18 and 20. Whereas both wall members 12 and 14 are provided with the openings 22 and 24, respectively, through which the drive shaft 16 extends, each of these openings is provided with an enlarged portion on the opposed outer faces of the wall members 12 and 14 which receive the bearings 18 and 20, and, as will be readily apparent, prevent longitudinal displacement of the drive shaft with respect to the walls and the housing 10 by virtue of the engagement of the bearing 18 against the step shoulder portion 26 of the drive shaft as held thereagainst by the lock nut members 28 threaded onto the end portion 30 of the drive shaft an the engagement of the enlarged collar 32 against the bearings 20 in the manner shown. The collar 32 is, of course, integral with the drive shaft 16 and the collar has formed integrally therewith an eccentrically disposed sleeve 34 having stepped inner surfaces 36 and 38.

An eccentric shaft 40 has an enlarged collar 42 at one end received Within the sleeve 34 and bearing against the stepped surface 36 thereof so that the eccentric shaft is moved in an orbital path in response to rotation of the drive shaft 16. The other stepped surface 38 carries a bearing member 44 and a work carrying sleeve or arbor 46 is pressed into the inner race of this bearing to be supported concentrically of the eccentric shaft 40. The outer end of the eccentric shaft 40 is provided with a reduced end portion 48 upon which an outboard bearing member 50 is mounted for journaling the outer 2;; end of the -arbor---sleeve-46: The arbor sleeve-46 mm its outer end -recessed; as at 52, for receivi-ngthe bearing 50' and the double nut-assembly 54 is providedon'athe threaded "freeend 56 0f the-eccentric-shaft for main- -tai-ning the bearing 50in place. I

The outer surface of the-sleeve 46 is provided with a thrust collar portion SS beaPi-ngagainSt one side of the pin-ion gear member 60 I and forcing the opposite side thereof into engagementwith -the bearing 44, in cooperation with the lockout-54, anditis to'be noted that any =suitable key 53 is provided "for fixingsethe pinion gear 60 on the-arbor 'sle'eve 46 The -h0using-'1'0iis '-pr0 vided with a hub portion'62 within-whic'h" the-collar 32 is disposed and from which the eccentric shaft 40-and arbor sleeve 46 project andthis boss is provided wi-th a recessed portion64-which snug-1y but rotatably receives a ring gear member 66 formed with internalteeth 68 on its inner surface-and with worm teeth=70 "on its outer surface.-- A worm' shaft "member-72) having a "knurled operating-rod 7 4, -l' is journa led in the hub 62 and has a threaded portion =76'.-'ina-ting with the worm Y teeth: 70' -i-of the :ring gear :for, selectively positioning this member rotatably; within the shubviforra purpose; lhfililiwil'lnb Presently. pp nt,

The aforementioned pinion gear 60 is in mesh with the internal teeth 68 of the ring gear 66 such as to provide a controlled rotation of the arbor sleeve 46 as the latter is carried orbitally by the eccentric shaft 40, To fix the ring gear 66 within the hub 62, a thrust ring member 78 is provided which bears against the peripheral outer portion of the ring gear and is maintained in engagement therewith by means of an end cap member 80 detachably secured to the collar 32 by any suitable means, such as at least one post member 82, one such being shown in Figure l, and it is to be noted that the end cap member includes an annular plate portion 84 rigid therewith which bears against a bushing 86 in turn bearing against the collar 58 on the arbor sleeve 46 and serving to maintain this sleeve as well as the eccentric shaft 40 in longitudinally fixed position relative to the housing assembly. It is preferred that the posts 82 be rigid with the collar 32 and that suitable fasteners be provided for detachably securing the cap member 80 to these posts.

For the purpose of imparting rotation to the drive shaft 16, the same is provided with a pulley assembly 88 feathered or otherwise suitably afiixed thereto and any suitable drive means may be employed for imparting rotation to the drive shaft 16 through the medium of the pulley assembly 88.

A conventional grinding wheel is indicated generally by the reference character 90 and, as will be seen most clearly in Figure 2, this grinding wheel may be fed into the work in the direction of the arrow in that figure, it being, of course, understood that the mechanism for imparting the feeding and retracting motions of the grinding wheel is of an entirely conventional nature and forms no part of this invention. In Figure 2 also is shown a work piece 92 mounted on the arbor sleeve 46 and the inner and outer arcuated arrows in that figure respectively indicate the rotation of the work and the drive shaft. It is to be understood that the particular rotation shown is not critical inasmuch as these motions may be reversed, it being important only that the relative directions of rotation of the spindle and the work be opposite.

It is to be understood that for different sized polygon work pieces having different numbers of faces, it will be necessary to change the relationship existing between the ring and pinion gears, that is, number of teeth thereon, the eccentricity of the shaft 40 and the diameter of the grinding wheel 90. This can, of course, be determined mathematically and for the purpose of clarity, one example only is herein given. For example, to grind a fourteen sided polygon having a measurement of 2.771" between opposed faces thereof, a pinion gear having 70 teeth, a pitch of 20 and a pitch diameter of 3.5" is utilized in conjunction with a ring gear having 95 teeth, a pitch of 20 and a 4.75 pitch diameter. Also, the center distance between the eccentric shaft and the drive shaft will be 6.25 and the maximum and minimum diameters of the grinding wheel, respectively, will be 14" and 13". This particular set-up will grind successively every fifth fiat surface on the work piece, and it is to be understood that such grinding will continue until all of the surfaces have been ground. By setting of the ring gear member 66, the arbor sleeve 46 and work piece 92 may be rotated and preset about the longitudinal axis thereof to locate the flats on the work piece. The over-all diameter of the work piece or distance between opposed faces thereof is controlled by feeding the grinding wheel into the work in a conventional manner.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and changes may be resorted to, falling within the scope of the appended claim.

What is claimed as new is as follows:

In a grinding machine, a housing, a drive shaft journaled within said housing, an eccentric shaft carried by said drive shaft parallel to but offset from the axis of the latter, a work holding sleeve journaled on said eccentric shaft and projecting from said housing, an internally toothed ring gear mounted in said housing, a pinion gear fixed on said sleeve in mesh with said ring gear, and a rotary end cap for said housing carried by said drive shaft and through which said sleeve extends eccentrically thereof and fixing said sleeve longitudinally with respect to said drive shaft, said sleeve being journaled in said cap.

References Cited in the file of this patent UNITED STATES PATENTS 633,108 Pearson Sept. 12, 1899 1,531,565 Melling Mar. 31, 1925 2,372,374 Goddard Mar. 27, 1945 2,372,794 Ricks Apr. 3, 1945 2,505,745 Sharp Apr. 25, 1950 2,530,502 Baney Nov. 21, 1950 2,688,700 Lewis Sept. 7, 1954 FOREIGN PATENTS 684,741 Great Britain Dec. 24, 1952 

